Improving the aqueous solubility of HCV‐E2 glycoprotein epitope mimics by cyclization using POLAR hinges

• Published in: Journal of peptide science Vol. 26; no. 1; pp. e3222 - n/a
• Main Authors: Meuleman, Theodorus J., Cowton, Vanessa M., Patel, Arvind H., Liskamp, Rob M.J.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-01-2020; John Wiley and Sons Inc
• Subjects: Alkynes; Amino acid composition; Amino acid sequence; Amino Acid Sequence - genetics; Amino acids; Antibodies; Antibodies, Monoclonal - chemistry; Antibodies, Monoclonal - immunology; Biological activity; Conjugation; cyclic peptides; cyclisation method; Cyclization - immunology; ELISA; Enzyme-Linked Immunosorbent Assay; epitope mimics; Epitopes; Epitopes - chemistry; Epitopes - immunology; Glycoproteins; Hepatitis C - immunology; Hepatitis C - virology; Hepatitis C Antibodies - chemistry; Hepatitis C Antibodies - immunology; hepatitis C virus; Humans; Immunoassays; Peptides; polar hinge; Polarity; Protein biosynthesis; Protein purification; Solubility; Solubility - drug effects; synthetic vaccine; Vaccines; Vaccines, Synthetic - chemistry; Vaccines, Synthetic - immunology; Viral Envelope Proteins - chemistry; Viral Envelope Proteins - immunology; cyclic peptides; synthetic vaccine; epitope mimics; hepatitis C virus; cyclisation method; polar hinge; ELISA
• ISSN: 1075-2617; 1099-1387
• DOI: 10.1002/psc.3222

In this research we describe the improvement of the water‐solubility of cyclic epitope mimics based on the HCV E2 glycoprotein by incorporation of suitable polar hinges. The poor solubility of epitope mimics based on peptide sequences in the envelope (E2) protein hampered their synthesis and purification and made it very difficult to prepare the molecular constructs for evaluation of their bioactivity. Since changes in the amino acid composition are hardly possible in these epitope mimics in order to increase water‐solubility, a polar cyclization hinge may offer a remedy leading to a significant increase of polarity and therefore water solubility. These polar hinges were applied in the synthesis of better water‐soluble HCV‐E2 epitopes. An azide functionality in the polar hinges allowed attachment of a tetraethylene glycol linker by Cu‐catalyzed azide‐alkyne cyclo‐addition (CuAAC) for a convenient conjugation to ELISA plates in order to evaluate the bio‐activity of the epitope mimics. The immunoassays showed that the use of more polar cyclization hinges still supported anti‐HCV antibody recognition and did not negatively influence their binding. This significantly increased solubility induced by polar hinges should therefore allow for the molecular construction and ultimate evaluation of synthetic vaccine molecules.